Aloisi always had faith in Mebrahtu

Melbourne Heart coach John Aloisi said he urged hero Golgol Mebrahtu to believe in himself before his star turn against Perth on Saturday.

Without a goal in his previous 26 A-League appearances, the Sudanese-born attacker made his Heart debut when introduced in the 78th minute at AAMI Park on Saturday with their clash against the Glory looking headed for a draw.

But Mebrahtu burst onto a Josip Tadic pass in the 89th minute before finishing past Danny Vukovic to give his side a 1-0 win.

Aloisi said Mebrahtu had the potential to be a fantastic player and his message to the former Gold Coast United man was a simple one.

"Go score a goal," Aloisi said with a laugh when asked what his message to Mebrahtu was.

"I just said to believe in yourself and go at them because that's what he's got. His ability is brilliant.

"When he gets the ball and he starts running at players, it's very difficult to defend against.

"One thing we have been trying to teach him in training is making forward runs because he's so quick, he's hard to catch.

"Josip Tadic did very well when he turned his player and Gol saw that space and attacked that space and that's what we want from him."

It ended a long wait for the 22-year-old, who signed a three-year deal with the now-defunct Gold Coast United in 2009.

Aloisi, whose team jumped into sixth after the win, said he never spoke to Mebrahtu about his goalless record.

"I never discussed it with him. I just kept on saying that your finishing is good because it is," he said.

"I'm not going to lie to a player. If his finishing is no good I'll work harder on his finishing, but his finishing is very good with both feet.

"Maybe (he) just had that lack of confidence in front of goal.

"You have to understand that Gol hasn't played a lot of consistent football because he's had osteitis pubis and he's worked hard off the pitch to get that right."

Aloisi said he expected to have Socceroos trio Richard Garcia, Aziz Behich and Michael Marrone back on Tuesday, when their fitness could be assessed.

The 36-year-old praised Heart's defence, which included youth team full-backs Jeremy Walker and Sam Mitchinson, after keeping a second straight clean sheet.

"Our shape has been quite good all year and when your shape is good, teams are going to find it hard to create," Aloisi said.

"Sometimes you get stretched and sometimes you get caught on the break – that's a different story and that can happen, especially when you're attacking an opposition.

"When we're set up, it's very hard to break us down. (Put the clean sheets down to) just the belief in the players, knowing that we've got good shape, no matter who plays."